Electric heater



E. N. LIGHTFOOT.

ELECTRIC HEATER.

APPLICATION FILED MAR.3, 1920.

} 1,389,312. P Aug. 30,1921.

EDWIN N. LIGHTFOOT, OF NEW YORK, N. Y., ASSIGNOR TO THE CUTLER-HAMMER MFG. 00., OF MILWAUKEE, WISCONSIN, A CORPORATION OF WISCONSIN.

ELECTRIC HEATER.

Specification of Letters Patent.

Patented Aug. 30, 1921.

Application filed March 3, 1920. Serial No. 362,991.

To all whom it may concern:

Be it known that I, EDWIN N. Lren'rroor, a citizen of the United States, residing at New York, in the county of Bronx and State of New York, have invented new and useful Improvements in Electric Heaters, of which the following is a specification.

This heater.

More particularly it relates to a fiat electric heater having a resistor mounted within but insulated from a sheet metal casing.

An object of this invention is to provide an improved electric heater which may be employed as either a space or surface heater.

Another object is to provide an improved electric heater wherein connection with the resistor thereof is facilitated.

Another object is to provide terminals for electric heater which will permit of the mounting of the heater against a flat conducting base with the terminals insulated therefrom or the mounting of several heat-"- ers upon conducting bars extending through the terminals of the several heaters.

Other objects and advantages will appear from the following specification and claims.

An embodiment of this invention is illustrated in the accomipanying drawings in which:

Figure 1 is a perspective of a heater equi ped with a terminal posltioned 1n and insuiifted from one reinforcing plate thereof and opposite an aperture in the other plate.

Fig. 2 is a sectional View through the terminal.

Fig. 3 is a bottom plan of a heater with parts broken away to show construction.

Fig. i is a perspective of several heaters mounted upon conducting bars extending through the terminals thereof.

Fig. 5 is a view of the conducting bar with the terminals of I two heaters connected therewith, one terminal being in section.

The electric heater illustrated comprises a bottom reinforcing plate 10 having flanges 11 and 12 which may be bent over a top reinforcing plate 13 to form an lnclosure for a resistor 14. This resistor is in the form of a flat resistance ribbon wound upon insulainvention relates to an electric.

' lating strip 17. The rivet also extends The plates 10 and 13 are provided with apertures 20 and 21 positioned opposite each other. The insulating strip 16 extends over the aperture 21 to form a window therefor.

A hollow terminal rivet 22 extends through the aperture 21 and aperture 23 in the insuthrough an aperture in mounting strip 24 connected with one end of the resistor 14. The per phery of the aperture 21 is struck up to provide a greater separation between the hollow terminal rivet 22 and the reinforcing plate 13. Further insulation in the form of insulating washers 25 and 27 are provided. The ends of the hollow terminal rivet 22are expanded toclamp the various parts together. A metal washer 26 is provided between the terminal strip 24 and the expanded end of the rivet 22 to provide a bearing surface for the rivet. If desired, a terminal having a perforated base 30 and a perforated extension 31 may be provided and clamped in position with the other parts by means of the hollow terminal rivet 22. .This terminal permits of the connection of an electric conductor to the terminal by looping the end of the conductor through the aperture in the projection 31.

Apertures 8 and 9 provided in the ends of the plate 13 extending beyond the ends of the platelO are for use when the heater is to be mounted flat against a supporting base. A heater provided with the form of terminal shown may be mounted flat against a base of conducting material and secured thereto b means of screws or bolts extending through the apertures 8 and 9. With the heater mounted in this position the plate 10 thereof is in contact with the conducting base. The terminal rivet 22 is, however, insulated from the base due to the window formed by the insulated strip 16 which extends over the aperture 20. An electric conductor may be connected to the terminal rivet 22 or to the extension 31 of the angular terminal if the latter is provided.

Fig. 4 shows several heaters equipped with the above described form of terminal and mounted upon conducting bars 35 and 36 which extend through the hollow terminal rivets 22. When the heaters are mounted. in this manner a hole must be punched in the insulating strip forming the window for the aperture-20. It is obvious that when-a hole is punched. in this window the heaters may be readily mounted upon the conducting bars 35 and 36. It may be desirable to arrange the heaters upon these conducting bars very close together. If the projecting terminals 31 are in the way when the several heaters are mounted close together upon the conducting bars 35 and 36 each may be easily broken off at the point at which they are attached to the perforated base 30.

Fig. 5 shows one of the conducting rods which is threaded to accommodate a nut 37 upon each side of the terminal rivet 22 to clamp this rivet into good electrical contact with the conducting rod. These nuts 37 also serve to position the heaters upon the rods.

Heaters provided with the above described form of terminal may be mounted in either of'the two ositions as described.

Electric eaters have been provided which might be mounted against a fiat conducting base with the terminal of the heater insulated from the armor thereof and from the conducting base. Electric heaters having terminals through which conducting rods may ex-- tend for mounting the heaters thereon have also been provided. The present heater, however, has a decided advantage thereover for it may be mounted in either position. Therefore it is necessary to stock but one type of heater where before it was necessary to carry in stock two types.

The invention contained herein is of course susceptible of other embodiments and adaptations.

What I claim is:

1. An electric heater haying in combination a resistor, an insulating strip on each side of the resistor, one of the strips being provided with an aperture, a pair of sheet metal plates forming an inclosure for the insulated resistor and having alined apertures opposite the aperture in the insulating strip, and a hollow terminal rivet connected with the resistor and extending through the apertures of the insulating strip and the adjacent plate, the other insulating strip extending across the aperture in the adjacent plate to form an insulating window therefor. ;.2. An electric heater having in combination a resistor, a pair of sheet metal plates formlng an inclosure for the resistor and having alined oppositely positioned apertures, insulating strips separating the resistor from the plates, one of the strips extending over the aperture in the adjacent plate to form a removable window therefor, and a hollow rivet connected with the resistor and extending through the aperture of the opposite plate and insulated from both plates.

3. An electric heater having in combination a resistor, a sheet metal armor insulated from and surrounding the resistor and having alined apertures in opposite sides thereof, a hollow terminal rivet connected with the resistor and extending through one of the apertures, and a removable insulating covering for the other aperture.

4. An electric heater having in combination a resistor, a sheet metal armor insulated from and surrounding the resistor.- and having alined apertures in opposite sides thereof, a hollow terminal rivet connected with the resistor and extending through one of the apertures, and a removable insulating coveringfor the other aperture positioned within the armor.

5.' An electric heater having in combination a resistor, insulating strips on each side of the resistor, a pair of sheet metal plates forming an inclosure for the insulated resistor and having alined apertures over one of which the adjacent insulating strips extends to form a removable window therefor,

and a hollow terminal rivet connected with the resistor and insulated from and extend-' ing through the aperture in the other plate.

6. An electric heater having in combination a resistor, a sheet metal armor insulated from and surrounding the resistor, said armor being provided with alined apertures on opposite sides thereof, and a hollow ter-' minal rivet insulated from the armor and positioned in one of the apertures in alinement with the other aperture to permit the heater'to be mounted against a fiat surface with the terminal rivet insulated therefrom or upon a conducting rod in contact with the terminal rivet and extending through the alined apertures.

7. An electric heater having in combination a resistor, a casing insulated from and inclosing the resistor and having an aperture in the wall thereof, a removable insulating covering for the aperture, and means for connecting a conductor with the resistor when said insulating covering is removed.

8. An electric heater having in combination a resistor, a casing insulated from and inclosing the resistor and having an aperture in the wall thereof, a terminal positioned opposite the aperture and connected with the resistor, and a removable insulating covering for the aperture.

9. An electric heater comprising a casing having an aperture, a resistor within the casing and insulated therefrom, a terminal connected with the resistor and positioned opposite the aperture, and a removable insulating covering for the aperture positioned within 5 the casing.

11. An electric heater comprising a casing having an aperture, a resistor within the casing and insulated therefrom, and a rem0v-- able insulating covering for the aperture, whereby when said insulating covering is 10 removed a conductor may be connected with the resistor.

In witness whereof, I have hereunto subscribed my name.

EDWIN N. LIGHTFOOT. 

